Double-action pump cylinder

ABSTRACT

A pump apparatus for pumping fluid from a well has a cylinder having upper and lower ends with inlet ports, a hollow pump rod defining a plurality of pump rod entry ports, a travelling two-way valve separating a cylinder interior into variable volume upper and lower chambers and first and second one-way valves mounted to the cylinder to seal the inlet ports.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No.62/938,044 filed Nov. 20, 2019, which is hereby incorporated byreference.

BACKGROUND

Millions of rural community members and smallholder farmers insub-Saharan Africa and similar regions face a barrier to accessingsufficient quantities of water from high-yield boreholes. The majorityof these boreholes, drilled primarily by government agencies orphilanthropic organizations, have been installed with traditionalsingle-action manual pumps which limits the flow rate to approximatelyfour gallons per minute and blocks any alternative access to the water.The proposed cylinder provides a double-action design that can increasethe flow rates of these boreholes resulting in shortened queues fordrinking water and improved opportunities for irrigating gardens andwatering livestock, minimizing the negative impact of dry seasons.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an elevation drawing of a complete cylinder assembly.

FIG. 2 shows a half section view of a complete cylinder assembly insidea well casing.

FIG. 3 shows a top view of an upper one-way valve and stuffing box.

FIG. 4 is a section view of the upper one-way valve and stuffing box.

FIG. 5 shows a section view of a lower one-way valve body.

FIG. 6 shows a top view of a one-way seal plate.

FIG. 7 shows a top view of a lower one-way valve assembly.

FIG. 8 shows a section view of the lower one-way valve assembly.

FIG. 9 shows a top view of an inlet spacer.

FIG. 10 shows a section view of an inlet spacer.

FIG. 11 shows a top view of a middle seat.

FIG. 12 shows a full section view of a middle seat.

FIG. 13 shows a top view of a cup seal.

FIG. 14 shows a top view of a two-way seal plate.

FIG. 15 shows a top view of a two-way valve gasket.

FIG. 16 is a cross section showing the two-way valve shuttling as a pumprod descends.

FIG. 17 is a cross section showing the two-way valve shuttling as a pumprod ascends.

FIG. 18 is an elevation drawing of an alternative embodiment of acomplete cylinder assembly.

FIG. 19 is a half section view of the alternative embodiment of FIG. 18.

DESCRIPTION OF AN EMBODIMENT

The current disclosure is directed to a pump apparatus with abelow-waterline component that is innovative, cost effective, and highlyefficient. The below waterline component is a double-action pumpcylinder that will operate to a depth of at least 85 feet. Thedouble-action pump cylinder increases the flow rate from the well byeliminating the unproductive portion of each stroke cycle. This isaccomplished by terminating a hollow pump rod in a manner that capturesa traveling, two-way valve capable of lifting water to the surface onboth the up and down portion of each stroke cycle. The pump apparatuscan be located inside a cased well and fitted to a mechanized pumpjackor a manually operated design. The double-action pump cylinder disclosedherein may be retrofitted to most international lift-style pump systemsthat rely on the reciprocation of a pump rod string.

The double-action pump cylinder utilizes an affordable and easilymaintained valving system that reduces the number of opposing valvesrequired from four to three while maintaining a full intake of externalfluid on each direction of the stroke cycle. This double-action pumpsystem utilizes one-way valves located at the upper and lower ends ofthe cylinder that operate in line with the pump rod reciprocation andare capable of delivering meaningful quantities of fluid even whenlocated inside a cased well with a small inner diameter, for example adiameter as small as four inches. The double-action pump cylinderdisclosed herein includes a valve assembly at the end of a pump rod. Thevalve assembly, which is a two-way valve, travels with the pump rod andactuates the opposing one-way valves when traveling up or down. Thedouble-action pump cylinder can therefore significantly increase theflow rate over a traditional lift-pump cylinder of equal diameter andstroke length. There are a number of benefits provided by thedouble-action pump cylinder disclosed including:

-   -   Increased flow rate reduces mechanized operating costs    -   Increased flow rate impacts the total volume of water raised per        day    -   Low cost encourages dedicated below-ground components allowing        for custom designed installations, time savings when not        required at additional well locations, and protects the water        quality of the aquifer    -   Raises a specified amount of water (irrigation or drinking) in        less time allowing an above-ground mechanical assembly to        service multiple locations    -   Ability of cylinder and pump rod components to retrofit        prevalent international manual water pump installation (e.g.,        India Mark II and Afridev) increasing the gallon-per-minute        yield and potentially resulting in increased number of        beneficiaries and shorter wait times    -   Provides opportunity to affordably maximize high-yield boreholes        with options of larger diameter cylinders, longer stroke        lengths, and increased cycle speed    -   A common size of pipe, for example a common 1½″ pipe can be used        to lower and position the cylinder assembly at the correct depth        and support it during actuation and a common size pipe, for        example a common ¾″ pipe can provide a robust connection from        the surface to the cylinder's internal pump rod. The common 1½″        and ¾″ or other size pipes may be for example PVC pipes    -   The cylinder can be easily disassembled by the end user for        needed cleaning or replacing of seals

Referring now to the drawings, a pump apparatus 10 comprises a doubleaction pump cylinder 12. Double action pump cylinder 12 may be disposedin a well 5 and utilized to pump fluid therefrom. Well 5 in theembodiment described is a cased well, but pump apparatus 10 may be usedin an uncased well also. Double action pump cylinder 12 may be loweredin well 5 on a suspension pipe 16. Double action pump cylinder 12comprises a cylinder 15 with a cylinder interior 17. Cylinder 15 hasupper and lower ends 20 and 25, an upper valve assembly 30 and a lowervalve assembly 35. Pump apparatus 10 may further comprise a suspensionpipe 16 for lowering the cylinder 15 into the well 5. Upper and lowervalve assemblies 30 and 35 are check valves and more particularly areone-way check valves. Pump apparatus 10 includes a pump rod 40 thatextends into cylinder 15 through the upper end 15 thereof and isreciprocably disposed therein. A two-way valve 45 assembly is disposedabout pump rod 40 and is movable therewith, and is also movable relativethereto. The two-way valve 45 divides cylinder 15 into upper and lowervariable volume chambers as more completely described below.

Pump rod 40 is a hollow pump rod defining a pump rod interior 50, anddefining a plurality of pump rod perforations, four pump rod entry ports52 through a wall thereof. Fluid in cylinder 15 is communicated intopump rod interior 50 through pump rod entry ports 52 and is delivered tothe surface therethrough. The embodiment shown has four pump rod entryports 52 spaced equally about the pump rod, but more or less ports maybe used. Shoulder 53 is defined on pump rod 40 at the transition to anecked down portion 55, in which pump rod entry ports 52 are defined.Pump rod 40 has upper end 54 which may be connected to a delivery pipe57 to deliver fluid to the surface. A lower end 56 of pump rod 40 has aseal cap 58 connected thereto. Pump rod 40 thus terminates at travellingtwo-way valve 45. Seal cap 58 has an upper end 60 that will engagetwo-way valve 45 during the upward pull of the pump rod 40. Duringoperation of the pump apparatus, pump rod 40 will be reciprocated incylinder 15. Fluid will enter pump rod interior 50 through the pump rodentry ports 52 on both the upward and downward cycle of the pump rod 40in cylinder 15.

First, or upper one-way valve 30 is connected an upper end 20 ofcylinder 15 and is operable to seal the upper end 20 to prevent flowtherethrough during the upward movement of two-way valve 45 and topermit flow therethrough during downward movement of two-way valve 45.Upper valve 30 defines a central opening 62 therethrough. Pump rod 40passes through opening 62. One-way valve 30 comprises a valve body 64and a one-way seal plate 66. Valve body 64 defines a plurality of upperinlet ports 68 therethrough at the upper end of cylinder 15. Valve body64 in the embodiment described has three upper inlet ports. Fluid fromwell 5 will flow into cylinder 15 through upper inlet ports 68 duringthe down stroke cycle of the two-way valve 45. The embodiment describedincludes three upper inlet ports 68.

A stuffing box 70 extends from valve body 64 and is integrally connectedthereto. Stuffing box 70 may be separately made and connected to valvebody 64. An upper connector 72 connected to stuffing box 70 comprises agland seal 74 and a threaded extension 76. Extension 76 may be connectedto suspension pipe 16. Gland seal 74 is connected to stuffing box 70.Pump rod 40 is sealingly received in gland seal 74 and stuffing box 70and is reciprocable therein.

Valve body 64 includes a plurality of standoffs 80 and in the embodimentdescribed three valve standoffs 80. Valve standoffs 80 orient theone-way seal plate 66 and limit its vertical travel. One-way seal plate66 has a scalloped design as shown in FIG. 6. Seal plate 66 defines aplurality of scallops 82 at its outer periphery, and specifically hasthree scallops 82. Seal plate 66 defines opening 84 therethrough toallow pump rod 40 to pass therethrough. A plurality of cutouts 86provide clearance for valve standoffs 80. The scalloped designeffectively seals each of the upper inlet ports 68, while providingreduced restriction to the flow of incoming water around its perimeter.Washers 88 held in place by fasteners 89 threaded into standoffs 80limit the travel of one-way seal plate 66. One-way seal plate 66 closesupper inlet ports 68 on the upward cycle of pump rod 40 and two-wayvalve 45 to block flow therethrough, and moves downwardly to open upperinlet ports 68 on the downward cycle of pump rod 40 and two-way valve 45to allow fluid from well 5 to pass through upper inlet ports 68 at upperend 20 of cylinder 15.

Lower one-way valve assembly 35 is similar to upper one-way valveassembly 30, but has no stuffing box connected thereto. One-way valveassembly 35 has a valve body 90 with a plurality of standoffs 92 and inthe embodiment described three valve standoffs 92. One-way valveassembly 35 has a one-way seal plate 94. Valve standoffs 92 orient theone-way seal plate 94 and limit its vertical travel. One-way seal plate94 has a scalloped design like that shown with respect to upper one-wayvalve 30 as shown in FIG. 6. As a result, the seal plate in FIG. 6 showsthe numeric indicators for both of seal plates 66 and 94. Seal plate 94defines a plurality of scallops 95 at its outer periphery, andspecifically has three scallops 95. A plurality of cutouts 96 provideclearance for valve standoffs 92. The scalloped design effectively sealseach of lower inlet ports 98 defined in valve body 90 at the lower end25 of cylinder 15, but provides a reduced restriction to the flow ofincoming water around its perimeter. Lower valve assembly 35 has threelower inlet ports defined in valve body 90. Washers 100 held in place byfasteners 102 threaded into standoffs 92 limit the travel of one-wayseal plate 94. In FIG. 7, one of the standoffs 92 is shown without afastener 102 and washer 100 so that the cutout 96 and standoff 92 may beseen, but it is understood that a third fastener and washer will beincluded. One-way seal plate 94 closes lower inlet ports 98 on thedownward cycle of pump rod 40 and two-way valve 45 to block flowtherethrough, and moves upwardly to open lower inlet ports 98 on theupward cycle pump rod 40 and two-way valve 45 and allow fluid from well5 to pass through lower inlet ports 98 at lower end 25 of cylinder 15.The use of a neutral buoyancy material will be used to provide a rapidseal for one-way seal plates 66 and 94 and may be, for example,injection molded from polypropylene or polyethylene.

Thus, water, or other fluid from well 5 is directed into cylinder 15 anddelivered upward in pump rod interior 50 through pump rod entry ports 52during both the upward and downward movement of pump rod 40 and two-waytravelling valve 45. The upper one-way valve assembly 30 and lowerone-way valve assembly 35 are fixed to upper and lower ends 20 and 25respectively of cylinder 15 by way of tie rods 104 passing throughtie-rod tabs 106 and secured by lock nuts 108.

Two-way valve 45 divides cylinder interior 17 into upper and lowervariable volume chambers 110 and 112. Two-way valve 45 comprises anupper seal 120, a lower seal 120 a and a two-way seal plate 124positioned between the upper and lower seals 120 and 120 a. Two-way sealplate 124 has a central opening 125 therethrough. Pump rod 40 is movablesuch that the pump rod entry ports 52 are movable relative to thetwo-way seal plate 124. Pump rod entry ports 52 are positioned above thetwo-way seal plate 124 during upward movement of the travelling two-wayvalve 45 and below the two-way seal plate 124 during downward movementof the travelling two-way valve 45. Fluid from the lower variablechamber 112 is directed into the pump rod interior 50 through the pumprod entry ports 52 during downward movement of the two-way valve 45 andfluid from the upper variable chamber is directed into the pump rodinterior 50 thorough the pump rod entry ports 52 during upward movementof the two-way valve 45.

The upper and lower seals 120 and 120 a may comprise identical cup sealswith the lower cup seal simply being inverted. Cup seals 120 and 120 amay be for example standard cup leathers which provide a low cost,readily available, and proven method for an internal-cylinder seal.Additionally, cup leathers deliver a highly efficient means of conveyingwater with a low ratio of friction regardless of the travel speed of thevalve assembly. This is especially beneficial in a solar-powered systemto maximize yield during times of reduced energy input. Cup seals 120and 120 a may be a part of upper and lower seal assemblies 122 and 122a. Upper seal assembly 122 includes upper seal 120, inlet spacer 126 andmiddle seat 128. Inlet spacer 126 and middle seat 128, along with cupseal 120 are inverted to form the lower half of two-way valve 45 and areidentified with the subscript a. Trapped between the two middle seats128 and 128 a are two two-way valve gaskets 130 and 130 a located attwo-way seal plate 124. Two-way valve gaskets 130 and 130 a haveopenings 131 and 131 a, and form a part of two-way seal plate 124. Thehalf section view of the assembled components of two-way valve assembly45 shows a design departure from traditional lift-pump valves in thatthere is no fixed connection to a solid pump rod. Rather, two-way valveassembly 45 is slidably connected to pump rod 40 so that it movestherewith but is also movable relative thereto.

The double-action pump cylinder thus incudes upper and lower sealingassemblies 122 and 122 a in the two-way valve 45 with a spacetherebetween. Inlet spacers 126 define a hydrodynamic entry profile 132to facilitate the transfer of water through its center 134 from the cupseal 120 to an interior 136 of the two-way valve 45. An outer surface138 of inlet spacer 126 supports and maintains the internal profile ofcup seal 120. Middle seat 128 provides a center reservoir 140 where thetransfer of water from the interior 136 of two-way valve 45 into pumprod interior 50 occurs. The external profile 142 of a first surface 144of middle seat 128 provides a contoured support for the base of cup seal120 on one side and a centering inset 146 on a second surface 148 forthe two-way seal plate 124 on the other. Inlet spacers 126 and middleseats 128 may be injection molded from UHMW for durability anddimensional stability under water, but it is understood that otherprocesses for the manufacture are possible, and other materials may beused.

Two-way seal plate 124 with two-way valve gaskets 130 and 130 a arecentered and captured between middle seats 128 and 128 a. Opening 125 inthe two-way seal plate 124 and the openings 131 in valve gaskets 131 and131 a have internal diameters that are larger than an outside diameterof the machined neck 55 of pump rod 40 to avoid repeated contact whileproviding a centralizing stability to a fully lowered pump rod 40 duringshipping, installation, and operation. Two-way seal plate 124 functionsby being situated between two stationary limits 150 and 152 above andbelow pump rod entry ports 52. The upper limit 150 is defined on a sealring 154 disposed about neck 55 below shoulder 53 and the lower limit isdefined on seal cap 58. As pump rod 40 is raised and lowered, itshuttles the pump rod entry ports 52 above and below two-way seal plate124 as two-way seal plate 124 engages stationary limits 150 and 152 toseal one of the opposing variable volume chambers 110 and 112. When sealplate 124 engages top limit 150 the lower chamber 112 is sealed and whenseal plate 124 engages lower limit 152 upper chamber 110 is sealed.Stationary limits 150 and 152 limit the travel of two-way valve 45relative to pump rod 40, such that pump rod entry ports are positionedin the interior 136 of two-way valve 45 to receive water or other fluidin cylinder 15.

The internal two-way valving transition is created by the position ofpump rod 40 relative to the two stationary limits 150 and 152. FIG. 16shows a down stroke with contact between the seal ring 154 and two-wayvalve gasket 130 on two-way seal plate 124 resulting in an open upperone-way valve 30 and a closed lower one-way valve 35. FIG. 17 shows theresults of a small lift of the pump rod 40 as the seal cap 58 nowengages the two-way valve gasket 130 a reversing the opposing one-wayvalves 30 and 35. This shuttling effect brings the traditionalfour-valve double-action pump systems to a three-valve system whilemaintaining the full intake of external fluid on each stroke. The volumeof the variable upper and lower chambers 110 and 112 changes as the pumprod 40 reciprocates. On the downstroke, water, or other fluid from lowerchamber 112 is pushed into pump rod entry ports 52. In the lowermostposition of two-way valve 45 upper chamber 110 is filled with water.When the valve 45 is in its uppermost position, the lower chamber 112fills with water. The upstroke will cause fluid in upper chamber 110 tobe pushed into pump rod entry ports 40 and lower chamber 112 will befilled as one-way seal plate 90 a is lifted to open ports 98.

The operation of pump apparatus 10 is evident from the description anddrawings. Pump apparatus 10 is lowered into well 5 to a desired depth.Once at the desired depth, pump rod 40 may be reciprocated in cylinder15 manually, or with any type of mechanized pumpjack that willreciprocate pump rod 40. When pump rod 40 moves downwardly seal ring 154will engage two-way seal plate 124 to push two-way valve assembly 45downwardly with pump rod 40. Upper one-way seal plate 66 will movedownwardly and fluid from well 5 will pass through upper end 20 ofcylinder 15, and specifically through upper inlet ports 68 in valve body64 into upper variable volume chamber 110. Lower one-way seal plate 94will be pushed downwardly to cover lower inlet ports 98 in lower valvebody 90 to prevent fluid from passing therethrough at lower end 25 ofcylinder 15. Pump rod entry ports 52 will be positioned in interior 136of two-way valve 45 below two-way seal plate 124 and fluid from lowervariable chamber 112 will be urged into pump rod interior 50 throughpump rod entry ports 52. Fluid is delivered upwardly through pump rodinterior 50 to a delivery pipe 57 and ultimately to the surface.

The process is reversed on the upward movement of the pump rod 40. Whenpump rod 40 moves upwardly, pump rod 40 will move relative to two-wayvalve 45 until seal cap 58 engages two-way seal plate 124. Upon theengagement of seal cap 58 with two-way seal plate 124 two-way valveassembly 45 is pulled upwardly with pump rod 40. Upper one-way sealplate 66 will move upwardly to prevent flow of fluid from well 5 throughupper end 20 of cylinder 15, and specifically to prevent communicationof fluid from well 5 through upper inlet ports 68 in valve body 64.Lower one-way seal plate 94 will be pulled upwardly to uncover lowerinlet ports 98 in lower valve body 90 to allow fluid to passtherethrough at lower end 25 of cylinder 15 into lower variable volumechamber 112. Pump rod entry ports 52 will be positioned in interior 136of two-way valve 45 above two-way seal plate 124 and fluid from uppervariable chamber 110 will be urged into pump rod interior 50 throughpump rod entry ports 52. Fluid is delivered upwardly through pump rodinterior 50 to delivery pipe 57 and ultimately to the surface.

An additional embodiment is shown in FIGS. 18 and 19. The pump apparatus200 of FIG. 18 is similar in many ways to pump apparatus 10. Pumpapparatus 200 has double action pump cylinder 202 with generallyidentical features to double action pump cylinder 12 with a fewexceptions. Cylinder 204 has upper and lower portions 205 and 206 with agreater diameter 208 than a diameter 210 of a center portion 211. Inaddition, a two-way valve 212 does not include inlet spacers or middleseats. Instead, a two-way seal plate 214 has a profile to support upperand lower cup seals 216 and 218, which may be identical to cup seals 120and 120 a respectively. The operation of the additional embodiment isidentical to that described above.

Embodiments disclosed herein include:

Embodiment A: A pump apparatus for pumping fluid from a well thatincludes a cylinder having upper and lower ends suspended in the well,the upper and lower ends of the cylinder having inlet portstherethrough. A hollow pump rod defining a plurality of pump rod entryports in a wall thereof communicated with a pump rod interior isreciprocably disposed in the cylinder. A two-way valve is disposed aboutthe pump rod and movable therewith. The two-way valve separates acylinder interior into variable volume upper and lower chambers. A firstone-way valve is mounted to the cylinder above the two-way valve and isoperable to seal the inlet ports in the upper end of the cylinder duringupward movement of the two-way valve and to allow inflow of water intothe upper chamber of the cylinder during downward movement of thetwo-way valve. A second one-way valve is mounted to the cylinder belowthe two-way valve and is operable to seal the inlet ports in the lowerend of the cylinder during downward movement of the two-way valve and toallow inflow of water into the lower chamber of the cylinder duringupward movement of the two-way valve.

Embodiment B: A pump apparatus for pumping fluid from a well includes acylinder having upper and lower ends and defining a cylinder interior. Ahollow pump rod is disposed in the cylinder. The hollow pump rod definesa pump rod interior and defines a plurality of pump rod entry portscommunicating the cylinder interior with the pump rod interior. A firstcheck valve at an upper end of the cylinder is configured to permit flowinto the cylinder through the upper end thereof and to prevent flow fromthe cylinder to the well therethrough. A second check valve at the lowerend of the cylinder is configured to permit flow into the cylinderthrough the lower end and to prevent flow from the cylinder to the welltherethrough. A travelling valve is positioned between the upper andlower check valves and is movable with the pump rod. Water is directedinto and delivered upward in the pump rod interior during both theupward and downward travel of the travelling valve.

Embodiment C. A pump apparatus includes a cylinder disposed in andcommunicated with a well having fluid therein. A hollow pump rod definesa pump rod interior and is reciprocably disposed in the cylinder. Atravelling valve is positioned on the pump rod and is movable therewithand also movable relative thereto, the fluid in the cylinder beingdelivered into the interior of the pump rod as a result of thereciprocating of the pump rod in the cylinder.

Embodiments A, B and C may have one or more of the additional elementsand/or features in any combination.

The pump rod being movable relative to the travelling valve.

The travelling valve comprising an upper cup seal, a lower cup seal, anda two-way seal plate positioned between the upper and lower cup seals.

The pump rod having entry ports that are movable relative to the two-wayseal plate, the pump rod entry ports being positioned above the two-wayseal plate during upward movement of the pump rod and below the two-wayseal plate upon moving the pump rod downward in the cylinder.

Water from the upper variable chamber of the cylinder being directedinto the pump rod interior through the pump rod entry ports during theupward movement of the two-way valve in the cylinder and water in thelower variable chamber of the cylinder being directed into the pump rodinterior through the pump rod entry ports during the downward movementof the two-way valve.

The upper cup seal comprising an upward facing cup seal and the lowercup seal comprising a downward facing cup seal.

The lower cup seal comprising an inverted upper cup seal.

The upper end of the cylinder defining a plurality of upper inlet portstherethrough and the lower end of the cylinder defining a plurality oflower inlet ports therethrough.

The upper one-way valve configured to block flow into the cylinderthrough the upper inlet ports during upward movement of the travellingvalve and to permit flow therethrough during downward movement of thetravelling valve.

The lower one-way valve configured to block flow into the cylinderthrough the lower inlet ports during downward movement of the travellingvalve and to permit flow therethrough during upward movement of thetravelling valve.

The pump rod having a lower end terminating at the travelling valve.

An upper limit onto the pump rod and a lower limit on the pump rod, theupper and lower limits positioned to limit the travel of the pump rodrelative to the travelling valve.

Thus, it is seen that the apparatus and methods of the present inventionreadily achieve the ends and advantages mentioned as well as thoseinherent therein. While certain preferred embodiments of the inventionhave been illustrated and described for purposes of the presentdisclosure, numerous changes in the arrangement and construction ofparts and steps may be made by those skilled in the art, which changesare encompassed within the scope and spirit of the present invention.

What is claimed is:
 1. A pump apparatus for pumping fluid from a wellcomprising: a cylinder having upper and lower ends suspended in thewell, the upper and lower ends of the cylinder having inlet portstherethrough; a hollow pump rod reciprocably disposed in the cylinder,the pump rod defining a plurality of pump rod entry ports in a wallthereof communicated with a pump rod interior; a travelling two-wayvalve disposed about the pump rod and movable therewith, the two-wayvalve separating a cylinder interior into variable volume upper andlower chambers; a first one-way valve mounted to the cylinder's upperchamber and above the two-way valve and operable to allow the hollowpump rod to reciprocate through its center while allowing a seal to bemaintained during increased cylinder pressure between the pump rod andstuffing box; and a first one-way valve mounted to the cylinder abovethe two-way valve and operable to seal the inlet ports in the upper endof the cylinder during upward movement of the two-way valve and to allowinflow of water into the upper chamber of the cylinder during downwardmovement of the two-way valve; and a second one-way valve mounted in thecylinder below the two-way valve, the second one-way valve operable toseal the inlet ports in the lower end of the cylinder during downwardmovement of the two-way valve and to allow inflow of water into thelower chamber of the cylinder during upward movement of the two-wayvalve.
 2. The pump apparatus of claim 1, the pump rod being movablerelative to the two-way valve in addition to being movable with the pumprod.
 3. The pump apparatus of claim 1, the two-way valve comprising; anupper cup seal; a lower cup seal; and a two-way seal plate positionedbetween the upper and lower cup seals.
 4. The pump apparatus of claim 3,the pump rod entry ports movable relative to the two-way seal plate, thepump rod entry ports being positioned above the two-way seal plateduring upward movement of the pump rod and below the two-way seal plateupon moving the pump rod downward in the cylinder, water from the upperchamber being directed into the pump rod interior through the pump rodentry ports during the upward movement of the two-way valve in thecylinder and water in the lower chamber being directed into the pump rodinterior through the pump rod entry ports during the downward movementof the two-way valve.
 5. The pump apparatus of claim 3, the lower cupseal comprising an inverted upper cup seal.
 6. The pump apparatus ofclaim 3, the upper cup seal comprising an upward facing cup seal and thelower cup seal comprising a downward facing cup seal.
 7. The pumpapparatus of claim 1, fluid from the lower chamber being directed intothe pump rod interior through the pump rod entry ports during downwardmovement of the two-way valve and fluid from the upper chamber beingdirected into the pump rod interior thorough the pump rod entry portsduring upward movement of the two-way valve.
 8. A pump apparatus forpumping fluid from a well comprising: a cylinder having upper and lowerends and defining a cylinder interior; a hollow pump rod disposed in thecylinder, the hollow pump rod defining a pump rod interior and defininga plurality of pump rod entry ports communicating the cylinder interiorwith the pump rod interior; a first check valve at an upper end of thecylinder configured to permit flow into the cylinder from the wellthrough the upper end thereof and to prevent flow from the cylinder tothe well therethrough; a second check valve at the lower end of thecylinder configured to permit flow into the cylinder from the wellthrough the lower end and to prevent flow from the cylinder to the welltherethrough; and a travelling valve positioned between the upper andlower check valves and movable with the pump rod, water being directedinto and delivered upward in the pump rod interior during both theupward and downward travel of the travelling valve.
 9. The pumpapparatus of claim 8, the travelling valve comprising: an upper seal; alower seal; and a two-way seal plate positioned between the upper andlower seal, the pump rod being movable relative to the two-way sealplate.
 10. The pump apparatus of claim 9, the pump rod movable such thatthe pump rod entry ports are positioned above the two-way seal plateduring upward movement of the travelling valve and below the two-wayseal plate during downward movement of the two-way seal plate.
 11. Thepump apparatus of claim 8 further comprising: the upper end of thecylinder defining a plurality of upper inlet ports therethrough, thefirst check valve configured to block flow into the cylinder through theupper inlet ports during upward movement of the travelling valve and topermit flow therethrough during downward movement of the travellingvalve; and the lower end of the cylinder defining a plurality of lowerinlet ports therethrough, the second check valve configured to blockflow into the cylinder through the lower inlet ports during downwardmovement of the travelling valve and to permit flow therethrough duringupward movement of the travelling valve.
 12. The pump apparatus of claim8, the pump rod having a lower end terminating at the travelling valve.13. The pump apparatus of claim 8, further comprising: an upper limit onthe pump rod; and a lower limit on the pump rod, the upper and lowerlimits positioned to limit the travel of the pump rod relative to thetravelling valve.
 14. The pump apparatus of claim 13 the travellingvalve comprising a two-way seal plate in an interior thereof, the pumprod extending through the two-way seal plate, wherein the upper andlower limits engage the two-way seal plate during movement of the pumprod to limit the travel of the pump rod relative to the travellingvalve.
 15. A pump apparatus comprising: a cylinder disposed in andcommunicated with a well having fluid therein; a hollow pump roddefining a pump rod interior reciprocably disposed in the cylinder; atravelling valve positioned on the pump rod and movable therewith andalso movable relative thereto; and the fluid being delivered into theinterior of the pump rod as a result of the reciprocating of the pumprod in the cylinder.
 16. The pump apparatus of claim 15, furthercomprising: a seal cap at a bottom end of the pump rod, the pump roddefining a plurality of entry ports communicated with the pump rodinterior, the pump rod entry ports positioned in an interior of thetravelling valve.
 17. The pump apparatus of claim 16 the travellingvalve comprising: an upper seal; a lower seal; a two-way seal platebetween the upper and lower seal plates, the pump rod sealingly receivedin an opening in the two-way seal plate.
 18. The pump apparatus of claim17, the upper and lower seals comprising generally identical oppositefacing cup seals.
 19. The pump apparatus of claim 15 further comprising:a first check valve at an upper end of the cylinder positioned to allowflow into the cylinder only during downward movement of the pump rod;and a second check valve at a lower end of the cylinder positioned toallow flow into the cylinder only during upward movement of the pumprod.
 20. The pump apparatus of claim 15, the travelling valve dividingthe cylinder into variable volume upper and lower chambers, fluid beingdirected into the pump rod interior from the upper chamber during upwardmovement of the pump rod and fluid being directed into the pump rodinterior from the lower chamber during downward movement of the pumprod.